California businesses must treat same-sex domestic partners the same as married couples, the state Supreme Court ruled Monday in the case of a golf club that denied a family membership to a lesbian couple.

The unanimous ruling was the court's first on the state's domestic partner law, which took effect this year and granted to registered partners most of the rights of spouses under state law.

Jon Davidson, legal director of the Lambda Legal Defense and Education Fund and lawyer for the couple in the case, called the ruling "an important recognition of our humanity.''

While it was a victory for the 27,000 couples who have registered with the state as domestic partners, it fell short of the broad anti-discrimination mandate sought by their advocates.

The justices crafted a narrow decision and sidestepped arguments by Davidson and other gay-rights lawyers that a business policy favoring married couples discriminates on the basis of sexual orientation -- similar to arguments raised in a separate case challenging California's ban on same-sex marriage. There was no need to address that issue in this case, the court said Monday, because no evidence was offered that the golf club's policy was intended to discriminate against gays and lesbians.

Instead, the justices said the Unruh Act, a California law requiring businesses to treat customers equally, prohibits discrimination against registered domestic partners.

California first established a registry for domestic partners -- same- sex couples of any age and opposite-sex couples in which one partner is older than 62 -- in 1999. The law at first provided only limited benefits, including the right of hospital visitation, but was expanded this year to become the broadest such measure in the nation. It grants the equivalent of spousal status, except for joint tax filing under state law and the numerous rights of married couples under federal law. Monday's ruling extended the requirement of equal treatment to businesses.

Two initiatives being circulated for next year's state ballot would repeal the domestic partner law and also would write California's current ban on same-sex marriage into the state Constitution, derailing a case now on its way to the state's high court.

Monday's decision "raises the stakes in the pending initiatives, those that are preserving marriage along with the essence of marriage,'' said attorney Matthew Staver of Liberty Counsel, which represents sponsors of one of the proposed ballot measures.

The case involved a lawsuit filed in 2001 by B. Birgit Koebke and Kendall French of San Diego, a couple since 1993 and registered domestic partners since 2000. Koebke had bought a membership in the Bernardo Heights County Club for $18,000 in 1987 and sued after the club refused to grant French a family membership available to married couples. Members' spouses can golf for free, but unmarried guests have to pay $40 to $75 a round and can play only six times a year.

Lower courts ruled in the club's favor, saying the Unruh Act does not forbid discrimination based on marital status. But the state Supreme Court said marital status discrimination is prohibited in at least some circumstances -- in particular, when the customers are registered domestic partners.

"A business that extends benefits to spouses it denies to registered domestic partners engages in impermissible marital status discrimination,'' said Justice Carlos Moreno in the 6-0 ruling.

He noted that businesses can easily distinguish registered partners, who have documented their relationship with the state, from other couples or casual friends.

Like the decision to marry, a decision to enter into a domestic partnership results in "the creation of a new family unit with all of its implications in terms of personal commitment as well as legal rights and obligations,'' Moreno wrote. For those couples, he said, "the Legislature has granted legal recognition comparable to marriage.''

In other circumstances, Moreno said, a company's policy favoring married over unmarried customers can be justified by "legitimate business reasons.''

He said the country club in this case had offered legitimate reasons for denying membership to other unmarried couples -- for example, a desire to limit use of its facilities and an unwillingness to ask intrusive questions that might differentiate committed couples from social friends.

The same rationales would justify denying benefits to pre-2005 domestic partners, whose rights and responsibilities were less than they are under the current law, Moreno said. He noted that the former law contained no overall declaration of equality and made partnerships easier to dissolve than the divorce-type proceedings under current law.

Justice Kathryn Mickle Werdegar dissented on that point. She said domestic partners "were far more than friends'' under the former law, which required them to declare their exclusive commitment and joint residence in registering with the state.

John Shiner, a lawyer for the country club, called the ruling "a complete vindication of its conduct and procedures through last year,'' before the expanded domestic partners law took effect. He said Bernardo Heights would follow the new law but declined to say whether it would grant spousal memberships to domestic partners, citing the club's argument that it is a private association exempt from the Unruh Act. The state's high court rejected similar arguments from a Bay Area country club in a 1995 case.

Koebke, in a statement issued through her lawyers, called the ruling "a great victory for California families.'' As a result, she said, "Kendall and I are one step closer to being able to play golf at Bernardo Heights on an equal basis.''.

The California Supreme Court on Monday added considerable legal clout to the state's new domestic partner protections, concluding that private country clubs must treat same-sex partners the same as married couples.

The decision came in one of a series of gay rights cases that are serving as a prelude to the historic legal showdown over whether California's ban on same-sex marriage is unconstitutional, a matter that could be heard by the Supreme Court by the end of this year. In Monday's decision, the justices ruled that a San Diego country club violated California civil rights laws by refusing a spousal discount to a lesbian couple that it extends to married members.

While the ruling did not tip the court's hand in how it will view the gay marriage issue, the justices made it clear that the domestic partner law was intended to offer the same legal protections that married couples enjoy. The decision could give registered domestic partners stronger protections with a host of businesses, from mortgage lenders to health clubs.

``In creating domestic partnerships, the Legislature has also created a policy favoring such partnerships similar to the policy favoring marriage,'' Justice Carlos Moreno wrote for the court.

Legal experts say Monday's ruling could cut two ways in the ongoing challenge to the state's gay marriage ban -- it shows the court is receptive to gay rights arguments but also could be exploited by gay marriage foes who argue that same-sex couples don't need the right to marry because of the domestic partner law.

The San Diego case involves Birgit Koebke, who pays $500 a month in membership fees to the Bernardo Heights Country Club. Married members can have children, grandchildren and spouses play the golf course for free, but Koebke must pay for her partner, Kendall French, to golf, and she can be a guest only six times a year.

The couple sued, arguing that the policy was discriminatory under civil rights laws and that it also violated the domestic partner provisions that went into effect the beginning of this year. California Attorney General Bill Lockyer backed the couple in the Supreme Court.

A trial judge and a state appeals court both ruled in favor of the country club, which argued that California's civil rights law permitted businesses to distinguish between married and unmarried couples if they could show a legitimate business interest in their policy. Club attorneys maintained that they'd be unable to limit the number of members and face problems because of a lack of resources.

Club attorneys could not be reached for comment. But the Supreme Court unanimously rejected the club's argument, saying treating domestic partners Koebke and French equally posed no threat to the business.

``Extending the spousal benefit to her,'' the justices wrote, ``would not create the stampede on the fairway that the (club) appears to envision.''

The decision gives the partners a chance to seek damages from the club, although the court limited it to conduct since the new domestic partner law went in to effect. Kathryn Mickle Werdegar dissented from that part of the ruling.

The justices are expected to rule sometime this month on another major gay rights case, involving the custody rights of same-sex couples who have children through artificial reproduction. The Supreme Court also in the coming months must decide whether to tackle the gay marriage challenge immediately or leave the issue for a state appeals court to rule upon first.

A San Francisco judge earlier this year found the state ban on gay marriage unconstitutional.

Jon Davidson, legal director for the Lambda Legal Defense and Education Fund, a pro gay-rights organization, said the latest Supreme Court ruling was ``respectful'' of the rights of same-sex couples, but didn't alter the fact they should still be entitled to marry.

``It really didn't answer the question posed by the marriage cases about whether or not having a two-tiered system is constitutionally adequate,'' Davidson said. ``Of course, it isn't.''

SUMMARY: The California Supreme Court ruled that businesses cannot treat domestic partners differently from the way they treat married couples.

In a decision with profound implications for gay and lesbian couples in the Golden State, the California Supreme Court ruled Monday that the state's Domestic Partner Rights and Responsibilities Act of 2003 prohibits businesses from treating registered domestic partners differently from the way they treat married couples.

The ruling came in the case of B. Birgit Koebke, a member of the San Diego area Bernardo Heights Country Club, who sought membership rights for her domestic partner, Kendall French. Although Koebke had paid $18,000 to join the golf club, and although she continued to pay $500 a month in dues, her partners was considered a guest, not a family member. While other members enjoyed free golf and unlimited use of the facility with their husbands and wives, French was obliged to use one of her partner's six annual guest passes, sign in and pay greens fees. Unlike other family members, she could not sign for food or drink, or make use of the club on her own.

Starting in 1995, when their relationship began, Koebke repeatedly asked the club's managers to make an exception for French, who became her registered domestic partner when California's statewide partner program took effect in 2000. Not only did she meet a brick wall in response, but as time went on, she also became a pariah at the club, the subject of gossip and harassment over minor dress violations and other matters.

In the course of her dispute and subsequent lawsuit against the club, she also discovered that the club made many exceptions to the rules for heterosexual members, allowing unrelated partners and friends to use members' privileges, as well as grandchildren and others not specified in the bylaws.

Koebke's main claim, that marital status discrimination is a violation of state civil rights law, did not convince the lower court or the state appellate court that reviewed her case. The appellate court did leave open the possibility that the club was violating the law by enforcing its bylaws in an arbitrary fashion, but it closed the door to the idea that marital status discrimination was illegal in principle.

To some extent, the high court agreed, ruling that there could be legitimate business reasons for a company to condition some services on marital status. But the five-member majority also ruled that no such distinctions could be made between a registered domestic partner and a married spouse. Under the 2003 revision of the state domestic partner law, the Legislature explicitly stated that it intended to equalize the legal status of committed same-sex couples and married heterosexuals. As such, the court ruled, the two institutions must be given identical weight.

The case will now return to trial court, unless Bernardo Heights revises its policies, which is likely. In a comment to the Associated Press, the club's lawyer, John Shiner, said Bernardo Heights "will take whatever action is necessary to comply with the decision of the Supreme Court."

The case was argued by Jon Davidson, legal director of Lambda Legal. "Today's ruling," Davidson said in a statement on Monday, "brings gay and lesbian couples one step closer to equality. But at the end of the day, our clients are still left as second-class citizens, because they are barred from the right that would have eliminated this case in the first place, the right to marry."